PROJECT SUMMARY Heart failure is a chronic condition in which the heart muscle can’t pump enough blood to meet the body’s needs for blood and oxygen. Heart failure affects over 5 million Americans and it is a serious condition that can be life- threatening if left untreated. Decompensated heart failure is the leading cause of hospital readmissions in the US. A common symptom of decompensation is the development of peripheral edema. Detecting edema can provide important clinical information to healthcare providers regarding the severity of the patient's heart failure and help guide treatment decisions. However, currently patients are asked to watch for edema themselves by checking their weight or noticing swelling of the legs/ankles and signs are often missed until the late stages of decompensation. In this context there is a need for a remote monitor that can offer an earlier warning and permit telehealth interventions to reduce hospital readmissions. Using our previously developed FlexNIRS platform we propose to build and validate a multi-wavelength wearable edema and microcirculation monitor and conduct a pilot clinical trial in patients admitted due to decompensate cardiac failure in which we will seek to demonstrate that physiological parameters related to re-compensation can be followed non-invasively and thus support the future conduct of larger scale studies of at home monitoring to detect decompensation.